The invention relates to a device for monitoring a tubular belt conveyor system comprising the following:
a conveyor belt consisting of an elastomeric material, particularly with embedded tie rods, whereby the conveyor belt can be closed so as to form a tubular belt by overlapping its longitudinal edges to form an overlap area; as well as
other system components such as a driving drum, a reversing drum, support rollers, guide rollers, supporting structures, as well as other optional components, if need be.
Tubular conveyor belts (pipe conveyor belts for encapsulated conveyance) are predominantly employed where bulk material has to be conveyed in a relatively confined space through horizontal and vertical curves.
Such conveyor systems have been used in the last few years also for conveying material over distances longer than 1 kilometer by virtue of their special adaptability to the topographical conditions.
In addition to their adaptability to the terrain, the advantages offered by tubular belts include the protection of the transported material against environmental influences (rain, wind, etc.) and the protection of the environment against material dropping from the conveyor belt (ashes from power plants; gypsum etc.).
Problems arise in connection with the operation of tubular conveyor belts with the guidance of the overlapping parts of the belt. The support and guide rollers of the system are responsible for correctly running the tubular conveyor belt (DE-C-31 22 664). Said rollers are individually aligned depending on the course the conveyor system is running.
The function of said rollers is influenced by varying weather and temperature conditions and by the wear, as well as by design defects.
Moisture, for example, reduces the value of the friction between the roller and the conveyor belt, which results in guidance that is not optimal.
The tubular belt is opened for loading and unloading, i.e. it is driven into a horizontal position. If the area of overlap of the tubular belt has not been guided into the correct position, i.e. if said overlap area is located at the bottom instead of at the top, for example as it is running up on the ejecting drum, the conveyor belt will be folded or it will run off of the drum sideways. Both events lead to substantial damage to the tubular conveyor belt and have to be absolutely avoided for that reason.
Said problem has been solved until now by forcibly guiding the conveyor belt over finger rollers projecting into the cross section of the tubular belt (DE-C-34 17 718), among other measures. Said method is successful in most cases; however, it is afflicted with the substantial drawback that the conveyor belt is attacked and damaged by the finger rollers. Said method consequently does not represent any satisfying permanent solution.
Now, a device for monitoring a tubular conveyor belt system is introduced in laid-open patent specification DE-A195 22 757, which employs detectors specifically in the form of the two following variations:
The conveyor belt is provided on its outer side with a detectable color marking. This, however, requires that the surface marking will not be damaged or soiled, which, however, cannot be avoided in most cases. The result will then be that the system is no longer capable of fulfilling its function, or satisfying it only to a limited extent.
The conveyor belt comprises detectable integrated indicators in particular in conjunction with steel cable belts, whereby individual cables or cords are replaced by the indicator. The drawback in this case is that the behavior of the tie rods of the conveyor belt might be adversely affected.
Therefore, the problem of the invention is to provide a conveyor system that excludes the drawbacks described above. Furthermore, the aim is that the system can be employed for all types of conveyor belts (steel cable conveyor belts, textile conveyor belts, aramide conveyor belts), as well as for all kinds of different conveyor constellations (curves, uphill gradients etc.), namely under the aspect of encapsulated conveyance. Moreover, the aim is that the conveyor system is free of wear, low in maintenance, and economical with as little technical expenditure as possible.
Said problem is solved according to the characterizing part of claim 1 in that the device for monitoring the overlap area of the tubular belt is provided with an optoelectronic system which, in the event the desired overlap of the conveyor belt is deviating, initiates a corrective setting by means of the guide rollers or, if the corrective measures are not successful within a preset period of time, automatically effects the shutdown of the tubular belt conveyor system.
Useful variations of the invention are specified in claims 2 to 11.